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Environmental Biology & Health Division

  

 Dr. Ebenezer D. O. Ansah
(Senior Research Scientist/Head of Division)

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  Dr. Mike Osei-Atweneboana (Senior Research Scientist)

Dr. Gloria D. Addico
(Senior Research Scientist)

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Dr. Felix Akpabey
(Senior Research Scientist/OIC-Tamale)

Mr. George T. Mensah
(Research Scientist)

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Ms. Victoria Afutu-Vanderpuye
(Research Scientist)

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Mr. Mark Osa Akrong
(Research Scientist)

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Mrs. Regina Banu
(Research Scientist)

 

Mr. Gerald Quarcoo

(Research Scientist) 

3.1 ENVIRONMENTAL BIOLOGY AND HEALTH DIVISION 

The main objective of the Environmental Biology and Health Division is to enhance public health status of Ghanaians through sound environmental management, water pollution control strategies, preventive and control strategies for water-borne and other infectious diseases. The Division has expertise in the areas of microbiology, parasitology, entomology, aquatic flora and fauna, molecular biology and public health.

Activities of the Division include:

  • • Water quality monitoring  through microbial, algal and macro-invertebrate analyses;
  • • Microbiological analyses of drinking water, waste water  and other samples;
  • • Identification and management of invasive plants in Ghana;
  • • Isolation and production of  entomopathogenic bacteria used in biological control of disease vectors;
  • • Environmental impact assessment and watershed management;
  • • Research into water-related/borne parasitic diseases and other infectious diseases;
  • • Research into water-related vectors of diseases of public health importance to develop innovative strategies for  control and prevention;
  • • Molecular epidemiology studies and understanding the mechanism and genetics of drug resistance and the development of DNA based diagnostic tools;
  • • Consultancy in the establishment of science and  medical laboratories; and
  • • Training of scientists, technologists and students.

Details on the research and development activities of the Division are presented in the following sections. 

3.1.1 Ecological Study of the Water Storage Facility (WSF) at the Akyem Mines: Water-Borne Vectors and Water-Related Diseases

(Project Staff: Dr. Mike Yaw Osei-Atweneboana – Senior Research Scientist, Dr Ruby Asmah – Senior Research Scientist, Dr. Ebenezer Ansa – Research Scientist, Regina Ama Banu – Research Scientist, Dr. Gloria Addico – Research Scientist, Mr. Theodore Quacopome – Research Scientist and Dr K. A. Asante – Research Scientist)

One of the health risks of reservoirs and other water bodies is the potential for increased transmission of water-related diseases, especially parasitic infections supported by disease vectors. Vector-borne diseases account for 17 % of the estimated global burden of all infectious diseases (WHO, 2012). These diseases profoundly restrict socio-economic status and development in countries with high rates of infection, many of which are located in the tropical and sub-tropical regions. Vector-borne diseases are transmitted by vectors, such as mosquitoes, aquatic snails and ticks that have active role in the transmission of pathogens from one host to other causing serious diseases in human populations. 

The most deadly water-related vector-borne disease, malaria, caused an estimated 627,000 deaths in 2012 (WHO, 2012). Other water-related diseases include; lymphatic filariasis transmitted by mosquitoes, onchocerciasis transmitted by blackflies, schistosomiasis by aquatic snails and dracunculiasis by water fleas (Cyclops). The transmission of water-related diseases depends on many factors, however, the presence of vectors determine the risk of transmission. Therefore, understanding the ecological preferences of vector organisms in relation to reservoirs is an important step in identifying disease management options, especially controlling vector populations to complement more conventional treatment-based disease control strategies. The purpose of the study was to assess the distribution and relative abundance of vectors of water-related disease and their potential for infection in the water storage facility (WSF), River Pra and the associated land areas at the project site and to determine the prevalence and incidence of water-related diseases in the surrounding communities. The specific objectives were to:

  • • assess the distribution and relative abundance of vectors of water-related diseases in the WSF and River Pra and the associated land areas at the project site and the potential for water related diseases .
  • • assess the prevalence and incidence of water-related diseases in the project sites and the surrounding communities and make recommendations towards prevention and control of these diseases.

The scope of work included study design to assess the presence, the distribution and abundance of disease vectors in the WSF, River Pra and associated land areas in the project area; entomological and parasitological assessment of vectors of malaria, onchocerciasis and guinea worm infections as well as the intermediate host of schistosomiasis; and survey of water-related diseases in New Abiriem Government Hospital. 

Out of the four vectors of water-borne disease assessed, three vectors including mosquito vectors transmitting malaria; blackflies vectors transmitting onchocerciasis, and snails serving as intermediate host for schistosomiasis, and their associated diseases were identified (Table 2). The water conditions in the WSF do not favour breeding of blackflies. However, some channels of River Pra have suitable breeding sites characterized by fast flowing water but no blackfly larvae were found. This is likely due to the muddy nature of the river water which is attributed to illegal gold mining activities in the area.

 

Table 2: Occurrence of vectors and parasites of water-related diseases at the various sampling sites

Water-related diseases

Vectors identified to genus or species level

Causative

Agents

Source of water

No. of samples collected

No. of vectors infected

Parasite infection rates

Malaria

Anopheles larvae

Plasmodium falcipalrium

Ponds and Paddles

42

0

-

Culex larvae

NIL

Ponds and Paddles

65

0

-

Schistosomiasis

Bulinus globosus

Schistosoma haematobium

WSF

22

0

0%

Bulinus truncates

WSF

0

0

0%

Onchocerciasis

Simulium damnosum larvae

Onchocerca volvulus

River Pra

0

0

-

Simulium damnosum adults

Banks of

River Pra

96/4hrs

0

0%

Dracunculiasis

Cyclops

Dracunculus medinensis

WSF

0

0

0

 

 

The day-biting rate of blackfly was estimated as 184 bites/person/day and the monthly-biting rates (MBR) as 5704 bites/person/month. The blackfly abundance and the daily biting rate of 184 bites/person/day was a high biting nuisance for people working around the water abstraction point of River Pra and people working in the project sites. This will significantly affect work output since a lot of effort and time will be spent in driving away the flies. However, the absence of infections in the blackflies put the staff at no risk of onchocerciasis and this is mainly due to the mass drug administration of ivermectin, the drug used for the control of onchocerciasis in the study area and the surrounding communities.  The drug has impacted significantly on disease transmission resulting into zero transmission, if this effort continues, onchocerciais infections could be eliminated in the projects sites and the surrounding communities. 

The aquatic snails Bulinus globosus, the intermediate host for urinary schistosomiasis, were the only vectors found in the WSF. All snails assessed for parasite loads showed the absence of Schistosoma haematobium, making the WSF free of S. haematobium infection. It must however be noted that the snail populations should be monitored regularly for infections since stormwater and other sources could possibly introduce Schistosome parasites into the WSF. Currently the WSF is restricted to human’s activities, thus limiting humans as direct source of infection. However, if the surrounding communities are given access to the reservoir, there would be the potential for schistosomiasis transmission in the project area and the surrounding communities. 

There were no vectors of malaria found in the WSF, however the survey carried out in five ponds and puddles in the project site showed the presence of mosquitoes. A total of 42 Anopheles larvae, the vectors of malaria and 65 Culex larvae, a non-vector of malaria were identified. Unlike Anopheles, the Culex is mainly responsible for nuisance biting. The presence of Anopheles spp in the study area indicates the potential for malaria transmission in the study area and the surrounding communities. 

Laboratory analysis of all water samples collected from the WSF showed that Cyclops were not present in the WSF. There was no potential for the transmission of dracunculiasis in the study area. Currently, the disease is on the verge of eradication globally and Ghana has made significant advancement towards the elimination of Guinea worm infection in the country. 

The occurrence of water-related diseases in the New Abirem Government Hospital and surrounding communities reduced significantly in the first six month of 2014 compared to that of same period in 2013. Within the first six months of 2013, the prevalence of water-related diseases ranged from 15.22-27.97 % for malaria, 4.87-11.32 % for diarrhoea, 0.04-1.02 % for schistosomiasis and 0-0.08 % for onchocerciasis. However, for the first six months of 2014, the prevalence of the diseases were relatively lower ranging from 5.52-14.4 % for malaria, 0.13-3.69 % for diarrhoea, 0.03-0.30 % for schistosomiasis, while there were no occurrences of onchocerciasis and guinea worm infections. These successes were attributed to effective campaign on public health diseases, public health education and effective implementation of mass drug administrations for diseases like onchocerciasis and schistosomiasis. The annual prevalence of malaria decreased from 22.5 % in 2013 to 10.4 % in 2014, showing a significant decrease (p<0.001) of 12.6 %. There was also a significant reduction (p=0.005) of 6 % in diarrhoea prevalence from 7.35 % in 2013 to 1.35 % in 2014. A significant decrease (p=0.05) of 0.45 % was realized in schistosomiasis prevalence from 0.56 % in 2013 to 0.11 % in 2014 while for onchocerciasis there was a decrease of 0.02 % in prevalence from 0.02 % in 2013 to zero in 2014. Data from the New Abirem Government Hospital highlighted five water-related diseases reported monthly between January 2013 and June 2014 (Figures 3 – 5). 

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Figure 3: Prevalence of water-related diseases recorded between January and December 2013 in New Abirem Government Hospital

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Figure 4: Prevalence of water-related diseases recorded at the New Abirem Government Hospital between January and June 2014

 

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Figure 5: Prevalence of water-related diseases recorded at the New Abirem Government Hospital between January and June each year for 2013 and 2014

 

 

The vector and parasitological study conducted in the WSF, the associated land area and the Pra river basin showed the presence of only aquatic snails in the WSF, mosquitoes in the associated land area while blackflies were found in and around the Pra river basin and the associated project sites. Though the vectors sampled in these areas were free of the disease-causing parasites, the assessment of the water-related diseases in the New Abirem Government Hospital revealed the occurrences of the water-borne diseases including schistosomiasis, makes this disease a potential risk in the WSF area as well as malaria in the project area. Currently, the restricted access to the WSF makes the risk of Shistosoma haematobium infection in the project area very minimal, however, should the surrounding communities be given access to the WSF, there will be potential of Shistosoma haematobium infection in the area. On the other hand, it is interesting to note that the prevalence of onchocerciasis in the surrounding communities is near zero and with the continuous ivermectin treatment and good treatment coverage; there will be the possibility of onchocerciasis elimination in these communities. Malaria however, remains a major problem in the area, though significant reduction has been observed in 2014, efforts should be made to develop effective control strategy including vector control and adoption of bed nets to bring the disease under control.

Recommendations made included: 

  •  Clearing of all aquatic weeds in and around the WSF before public access is given to surrounding communities.
  •  Monitoring of aquatic snails for schistosome parasites and if possible the application of molluscicides to control the aquatic snails. 
  •  Though onchocerciasis has reduced drastically in the surrounding communities, mass drug administration of ivermectin should continue and entomological and epidemiological studies conducted to established possible elimination of onchocerciasis in the district.
  •  Controling of blackfly biting nuisance in some specific areas in the project areas may be considered, especially for people working around the Pra water abstraction point.
  •  Maintaining the decrease in malaria prevalence observed in 2014 to ensure that the devastating effects of malaria in our communities are reduced significantly.

3.1.2 Cloning and Genetic Analysis of Gamma Amino Butyric Acid (GABA) and P-glycoprotein Genes for Development of Molecular Genetic Markers

(Project Staff: Dr. Mike Yaw Osei-Atweneboana – Senior Research Scientist, Mr. Samuel Armoo – Research Scientist, Mr. Kwadwo Frempong Kyeremeh – Technical Officer, Mr. Ernest Tawiah Gyan – Technical Officer, Mr. Edward Jenner Tettevi – Technical Officer)

Ivermectin (IVM) has been in operational use for the control of onchocerciasis since 1987 and still remains the only available drug for mass treatment for the disease worldwide. This control strategy has achieved great successes over the years, as millions of people living in endemic communities have been protected from Onchocerca volvulus-induced blindness and other clinical symptoms of the disease. However, recent reports have indicated that the parasite, O. volvulus, is responding sub-optimally to ivermectin and have suggested possible emergence of resistance. The study was therefore undertaken to determine the correlation between the phenotypic characteristics of O. volvulus female worms and the genotypes found in haemoncus (HG1) and P-glycoprotein (P-gp) genes, and identify associated single nucleotide polymorphisms (SNPs) that could be used to develop genetic markers for detection of IVM resistance. The specific objectives of the study were to:

  •  clone a fragment of genomic DNA sequence of gamma amino butyric acid (GABA) receptor gene, HG1 from O. volvulus;
  •  identify genetic changes in HG1 and P-gp genes associated with worm phenotypes  showing good and poor IVM response; and
  •  determine specific genetic changes, including SNPs in HG1 and P-gp genes exclusively associated with worm phenotypes showing poor IVM response. 

During the reporting year, cloning of full length genomic DNA sequence of GABA receptor gene, HG1 and genetic analysis of both HG1 and P-gp genes were carried out for genetic marker discovery. Genomic DNA was extracted from 100 individual adult females of O. volvulus obtained from communities responding sub-optimally to IVM and those showing normal response to IVM treatment. A set of gene specific primer pairs were designed from the previously cloned DNA sequences of HG1 gene to amplify a fragment of about 1,400 bp using Polymerase Chain Reaction (PCR) technique. The general amplification conditions for the PCR was an initial denaturation at 95OC for 2 min, followed by 35 cycles of 95 OC for 45 seconds, an annealing temperature of 52 OC for 45 seconds, initial extension temperature at 68OC for 1 min and a final extension at 68OC for 5 min. Proof reading Taq polymerase was used to avoid errors during PCR amplification. The PCR products obtained were examined on a 1% agarose gel electrophoresis at 110 volts and visualized using the Bio-Rad gel documentation system Gel Doc.

Also the full length genomic DNA sequence of P-gp gene of about 10,000 bp was retrieved from the gene bank and six sets of gene specific primers pairs were designed from various polymorphic sites, including: one region from ATP binding domain of the Nucleotide Binding domain–1 denoted by Walker A1/P-loop; two regions from the ATP binding domain of Nucleotide binding domain–2 denoted by Walker A2/P-loop and the iodide transport defect 14 (ITD14); two regions from the Transmembrane Domain–1, called iodide transport defect 1 (ITD1) and iodide transport defect 4 (ITD4); and the sixth region, the Linker region. All six regions were amplified by PCR using DNA extracted from 50 individual female O. volvulus worms for each region. All PCR products were cleaned and sent for DNA sequencing.

A total of 100 adult female worms from both sub-optimal and good IVM response individuals were amplified by PCR technique and sequenced using the traditional Sanger sequencer. A fragment of 1395 bp of GABA receptor gene, HG1 was successfully cloned and sequenced as indicated in Figure 6. The six regions that were amplified, for the P-gp gene, ranged between 300bp and 979 bp. A total of 100 individual worms were amplified and sequenced successfully for each region. The ITD1 region produced a sequence of 684 bp. An agarose gel image showing the fragment size of ITD1 after PCR amplification is shown in Figure 7 whiles the sequences of ITD1 and WALKER A1/P-LOOP regions are shown in Figures 8 and 9. Bioinformatics analysis using Sequencher software is currently on-going to identify various single nucleotide polymorphisms (SNPs) and allele frequencies to determine the genetic changes that are associated with sub-optimal IVM response. 

 

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Figure 7: Image of an agarose gel showing DNA bands of O. volvulus samples amplified from P-gp gene, M4: 100bp DNA marker, S3 – S20: DNA samples from O. volvulus (some samples did not amplify successfully), N2: Negative control

 

3.1.3 Water Quality Studies in Relation to Cage Fish Culture in Nandomguo, Kokoligu, Baleofiri and Yeliyiri Reservoirs in Upper West Region

(Project Staff: Mr. MichaeKumi – Research Scientist, Mr. Gerard Quarcoo – Research Scientist and Mr. Etornyo Agbeko – Research Scientist)

The study was carried out in collaboration with Zoomlion Ghana Limited, Wa; Fisheries Commission; Ministry of LocaGovernment and RuraDevelopment (MLGRD); and Foreign Affairs, Trade and Development Canada (DFATD). The objectives were to:

  •  monitor the physical, chemical and biological water quality parameters that influence fish production;
  •  identify the source of pollutants that are hazardous to fish production in the reservoirs; and
  •  make recommendation to control the pollution of the reservoir to ensure sustainable and profitable caged fish production.

In the reporting year, quarterly water quality monitoring samples were taken from the up-, mid- and down-stream sections of the Nandomguo, Kokoligu, Yeliyiri and Baleofiri reservoirs and microbial analysis carried out in the laboratory. Bacteriological parameters such as total coliform, faecal coliform, E. coliSalmonella spp. and total heterotrophic bacteria were determined. 

The study showed that though the bacterial levels varied during the one year period for the reservoirs compared to their background values, all the reservoirs had their bacterial levels below the USEPA and WHO permissible levels of 10000 CFU/100ml and 1000 FC/100ml, respectively, for fresh and wastewater for aquaculture with the exception of the Kokoligu Reservoir which had higher levels of bacterial than the permissible levels during the 4th quarter. These higher levels could be attributed to heavy rainfall carrying sediments and faecal matter of animals such as cattle containing higher bacterial counts into the reservoir as these animals were seen to be grazing at the bank of the reservoir during the sampling periods. The bacteriological results for Total coliform (TC), Faecal coliform (FC), E. coli, Total heterotrophic bacteria (THB) and Salmonella spp. (SS) analysed for Baleofiri, Yeliyiri, Nandomguo and Kokoligu reservoirs in the Upper West Region are shown in Table 3.